Four months after two people became infected with HIV through tainted blood screened and distributed by Florida Blood Services, the agency has announced that it will test two new systems that remove bacteria, HIV, and other viruses from donated blood, the St. Petersburg Times reports. FBS will conduct clinical tests of two different blood-cleansing methods--one that uses ultraviolet light to kill pathogens and another that uses chemicals to destroy bacteria and viruses. The agency hopes to begin recruiting volunteers for the clinical tests by April.

Currently blood is screened by the agency by pooling samples from 16 to 24 donors and testing the pooled blood for pathogens. If a pathogen is detected, each blood sample is tested individually and all infected blood products are destroyed. But current testing methods are not foolproof, and blood from donors who have been infected with HIV a few days before donating often does not test positive for HIV. Although two people were infected with HIV from FBS blood products, separate investigations by the Food and Drug Administration and the Florida Department of Health found that FBS's blood handling, testing, and storage procedures were in compliance with federal and state regulations. Health officials estimate that the risk of HIV infection from donated blood is more than 1 million to 1.